1. Field of the Invention
The present invention relates to a laser diode driver, and more particularly to a laser diode driver utilizing a monolithic semiconductor device with a thyristor-like structured switch.
2. Description of the Prior Art
We have already proposed a high power, high pulse repetition frequency (PRF), compact, pulsed laser diode driver utilizing a monolithic semiconductor device in the pending U.S. patent application Ser. No. 08/247,064, allowed Feb. 7, 1995. Such a monolithic semiconductor device, in which the energy storage capacitor and the optically activated semiconductor switch are integrated onto a single high resistance semiconductor wafer substrate, is used to minimize the stray inductance and stray capacitance effects. The result is a pulsed, high power laser driver capable of fast turn on and turn off times and high PRF.
In an ideal operating condition, the output laser pulse width is determined by the two-way wave transit time in the energy storage non-uniform impedance stripline. In addition, the non-uniform impedance stripline induces current gain. Therefore, utilization of the non-uniform impedance stripline structure as the energy storage capacitor and the optically activated semiconductor switches as a switch is very effective way for the generation of the high peak power, high PRF, laser pulses with extremely narrow pulsewidth.
However, operation of this device depends on an optically activated semiconductor switch, in which it requires triggering optical energy to turn on the switch. In general, as the power capability of the ordinary optically activated switch increases, the required triggering optical energy level goes up rapidly. As a result, the capability and performance of the triggering laser driver, depending on the optically activated device, degraded rapidly.